Transduction of Cu, Zn-superoxide dismutase mediated by an HIV-1 Tat protein basic domain into human chondrocytes

Therapeutic Potential of Superoxide Dismutase Fused with Cell-Penetrating Peptides in Oxidative Stress-Related Diseases

Superoxide dismutase (SOD) is a well-known cellular antioxidant enzyme. However, exogenous SOD cannot be used to protect tissues from oxidative damage due to the low permeability of the cell membrane. Cell-penetrating peptides (CPPs) are a class of short peptides that can cross the cell membrane. Recombinant fusion protein that fuses SOD protein with CPP (CPP-SOD) can cross various tissues and organs as well as the blood-brain barrier. CPP-SODs can relieve severe oxidative damage in various tissues caused by radiation, ischemia, inflammation, and chemotherapy by clearing the reactive oxygen species, reducing the expression of inflammatory factors, and inhibiting NF-κB/MAPK signaling pathways. Therefore, the clinical application of CPP-SODs provide new therapeutic strategies for a variety of oxidative stress-related disorders, such as Parkinson's disease, diabetes, obesity, cardiac fibrosis, and premature aging.

Cytokine Directed Chondroblast Trans-Differentiation: JAK Inhibition Facilitates Direct Reprogramming of Fibroblasts to Chondroblasts

Osteoarthritis (OA) is a degenerative disease of the hyaline articular cartilage. This disease is progressive and may lead to disability. Researchers proposed many regenerative approaches to treat osteoarthritis, including stem cells. Trans-differentiation of a fully differentiated cell state directly into another different differentiated cell state avoids the disadvantages of fully reprogramming cells to induced pluripotent stem cells (iPSCs) in terms of faster reprogramming of the needed cells. Trans-differentiation also reduces the risk of tumor formation by avoiding the iPSC state. OSKM factors (Oct4, Sox2, Klf4, and cMyc) accompanied by the JAK-STAT pathway inhibition, followed by the introduction of specific differentiation factors, directly reprogrammed mouse embryonic fibroblasts to chondroblasts. Our results showed the absence of intermediate induced pluripotent stem cell formation. The resulting aggregates showed clear hyaline and hypertrophic cartilage. Tumor formation was absent in sub-cutaneous capsules transplanted in SCID mice.

TAT-mediated intracellular delivery of carboxypeptidase G2 protects against methotrexate-induced cell death in HepG2 cells

Side effects of methotrexate (MTX) especially hepatotoxicity limits clinical applications of this anticancer agent. Carboxypeptidase G2 (CPG2) is administrated for the treatment of elevated plasma concentrations of MTX. In this study, we have investigated the intracellular delivery of CPG2 fused to the transactivator transduction domain (TAT) and its protective effects against MTX-induced cell death of HepG2 cells. We have observed that both native and denatured forms of the enzyme transduced into the HepG2 cells efficiently in a concentration and time-dependent manner. The denatured protein transduced with higher efficiency than the native form and was functional inside the cells. MTX exposure significantly decreased HepG2 cell viability in a dose- and time-dependent manner. The cell viability after 24 and 48 h of incubation with 100 μM MTX was reduced to 44.37% and 17.69%, respectively. In cells pretreated with native and denatured TAT-CPG2 protein the cell viability was 98.63% and 86.31% after 24 and 48 h, respectively. Treatment with MTX increased the number of apoptotic HepG2 cells to 90.23% after 48 h. However, the apoptosis percentage in cells pretreated with native and denatured TAT-CPG2 was 21.49% and 22.28%, respectively. Our results showed that TAT-CPG2 significantly prevents MTX-induced oxidative stress by decreasing the formation of ROS and increasing the content of glutathione (GSH) and catalase activity. Our finding indicates that both native and denatured TAT-CPG2 strongly protect HepG2 cells against MTX-induced oxidative stress and apoptosis. Hence, intracellular delivery of CPG2 might provide a new therapeutic strategy for protecting against MTX mediated cytotoxicity.

PEP-1-FK506BP12 inhibits matrix metalloproteinase expression in human articular chondrocytes and in a mouse carrageenan-induced arthritis model

The 12 kDa FK506-binding protein (FK506BP12), an immunosuppressor, modulates T cell activation via calcineurin inhibition. In this study, we investigated the ability of PEP-1-FK506BP12, consisting of FK506BP12 fused to the protein transduction domain PEP-1 peptide, to suppress catabolic responses in primary human chondrocytes and in a mouse carrageenan-induced paw arthritis model. Western blotting and immunofluorescence analysis showed that PEP-1-FK506BP12 efficiently penetrated chondrocytes and cartilage explants. In interleukin-1β (IL-1β)-treated chondrocytes, PEP-1-FK506BP12 significantly suppressed the expression of catabolic enzymes, including matrix metalloproteinases (MMPs)-1, -3, and -13 in addition to cyclooxygenase-2, at both the mRNA and protein levels, whereas FK506BP12 alone did not. In addition, PEP-1-FK506BP12 decreased IL-1β-induced phosphorylation of the mitogen-activated protein kinase (MAPK) complex (p38, JNK, and ERK) and the inhibitor kappa B alpha. In the mouse model of carrageenan-induced paw arthritis, PEP-1-FK506BP12 suppressed both carrageenan-induced MMP-13 production and paw inflammation. PEP-1-FK506BP12 may have therapeutic potential in the alleviation of OA progression. [BMB Reports 2015; 48(7): 407-412]

Intestinal cell targeting of a stable recombinant Cu-Zn SOD from Cucumis melo fused to a gliadin peptide

The mRNA encoding full length chloroplastic Cu-Zn SOD (superoxide dismutase) of Cucumis melo (Cantaloupe melon) was cloned. This sequence was then used to generate a mature recombinant SOD by deleting the first 64 codons expected to encode a chloroplastic peptide signal. A second hybrid SOD was created by inserting ten codons to encode a gliadin peptide at the N-terminal end of the mature SOD. Taking account of codon bias, both recombinant proteins were successfully expressed and produced in Escherichia coli. Both recombinant SODs display an enzymatic activity of ~5000U mg(-1) and were shown to be stable for at least 4h at 37°C in biological fluids mimicking the conditions of intestinal transit. These recombinant proteins were capable in vitro, albeit at different levels, of reducing ROS-induced-apoptosis of human epithelial cells. They also stimulated production and release in a time-dependent manner of an autologous SOD activity from cells located into jejunum biopsies. Nevertheless, the fused gliadin peptide enable the recombinant Cu-Zn SOD to maintain a sufficiently sustained interaction with the intestinal cells membrane in vivo rather than being eliminated with the flow. According to these observations, the new hybrid Cu-Zn SOD should show promise in applications for managing inflammatory bowel diseases.

Pyridoxal-5'-phosphate phosphatase/chronophin inhibits long-term potentiation induction in the rat dentate gyrus

Pyridoxal-5'-phosphate (PLP)-phosphatase/chronophin (PLPP/CIN) directly dephosphorylates actin-depolymerizing factor (ADF)/cofilin as well as PLP. Although PLPP/CIN plays a role in the regulation of F-actin and vitamin B(6) metabolism, there is no direct evidence to support a correlation between PLPP/CIN and F-actin polymerization during long-term potentiation (LTP) induction. In this study, we investigated whether the expression of PLPP/CIN is altered following LTP induction, and whether Tat-PLPP/CIN transduction affects LTP induction in the rat dentate gyrus (DG). PLPP/CIN immunoreactivity was markedly decreased in dentate granule cells after the induction of LTP. Tat-PLPP/CIN transduction (20 and 200 microg/kg) decreased the efficiency of high frequency stimulus-induced potentiation of populations spike amplitude as compared to saline or Tat-protein-treated animals. The PLPP/CIN protein level showed an inverse correlation with phosphorylated ADF/cofilin levels and F-actin content. These findings suggest that PLPP/CIN-mediated actin dynamics may play an important role in the changes of morphological properties (dendritic spine reorganization) of the hippocampus in LTP.

Anti-arthritic effect of ginsenoside Rb1 on collagen induced arthritis in mice

BACKGROUND

The development of orally bioavailable, inexpensive inhibitors of tumor necrosis factor (TNF)-alpha is desirable for the treatment of rheumatoid arthritis (RA).

OBJECTIVE

To show the efficacy of ginsenoside Rb1 (G-Rb1), a ginseng extract, on the inhibition of TNF-alpha upregulation and on the inhibition of collagen induced arthritis (CIA).

METHODS

Peripheral blood mononuclear cells (PBMC), chondrocytes and fibroblast-like synoviocytes (FLS) were stimulated with interferon(IFN)-gamma, lipopolysaccharide (LPS) or interleukin-1 in the presence or absence of G-Rb1. The concentrations of (TNF)-alpha in the culture supernatants were determined by ELISA. CIA was induced in DBA/1J mice and G-Rb1 was prophylactically administered from day 20 until day 39 following immunization. Histopathologic changes were scored, and the expression of TNF-alpha was evaluated by immunohistochemistry.

RESULT

G-Rb1 significantly inhibited TNF-alpha upregulation in PBMCs, FLS and chondrocytes induced by IFN-gamma, LPS or IL-1. Administration of G-Rb1 resulted in a significant amelioration of the clinical arthritis score in the CIA mice. Histology revealed that G-Rb1 reduced cell infiltration and cartilage destruction in the arthritic joint, which was accompanied by a significant decrease in TNF-alpha expression.

CONCLUSION

The utilization of G-Rb1 is a feasible approach to the treatment of RA or other diseases characterized by upregulation of TNF-alpha.

Inactivation and modification of superoxide dismutase by glyoxal: Prevention by antibodies

Glyoxal is an endogenous compound, the levels of which are increased in various pathologies associated with hyperglycaemia and other related disorders. It has been reported to inactivate critical cellular enzymes by promoting their cross-linking and perpetuates advanced glycation end-product (AGE) formation. In this study, we used superoxide dismutase (SOD) as a model to investigate the ability of specific anti-enzyme antibodies and monomer Fab fragments to protect against glyoxal-induced deactivation and aggregate formation. We found that glyoxal deactivated SOD, in a concentration and time-dependent fashion. The enzymatic activity was monitored spectrophotometrically and it was found that enzyme lost approximately 95% of its original activity, when exposed to 10 mM glyoxal for 120 h. SDS-polyacrylamide gel electrophoresis demonstrated the formation of high molecular weight aggregates in SOD samples exposed to glyoxal. Surface-enhanced laser desorption/ionization time of flight mass spectrometry (SELDI-TOF-MS) showed increase in relative molecular mass (M(r)), upon exposure to glyoxal. Specific anti-enzyme antibodies and monomer Fab fragments markedly inhibited SOD deactivation caused by glyoxal and decreased the extent of cross-linking or formation of aggregates. This protection by the antibodies or Fab fragments was specific since, other non-specific antibodies were not able to protect SOD. Previously, antibodies have been used to prevent aggregation of beta-amyloid peptides in Alzheimer and prion-protein disease. Our findings provide a new perspective, for use of antibodies to prevent the biomolecules against glycation-induced deactivation and alteration.